[PATCHv3 2/3] USB: Add a serial number parameter to g_file_storage module

Michal Nazarewicz
2010-07-08T20:51:21Z

From: Yann Cantin <yann.cantin@laposte.net>

This patch add a serial number parameter to the g_file_storage
module. There's validity checks against the string passed to comply
with the specs.

Signed-off-by: Yann Cantin <yann.cantin@laposte.net>
[m.nazarewicz@samsung.com: modified to use fsg_string_serial_fill]
Cc: Michał Nazarewicz <m.nazarewicz@samsung.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
---
drivers/usb/gadget/file_storage.c | 54 ++++++++++++++++++++++++++++++++++--
1 files changed, 51 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index f1e6956..9663176 100644
--- a/drivers/usb/gadget/file_storage.c
+++ b/drivers/usb/gadget/file_storage.c
@@ -56,7 +56,7 @@
* following protocols: RBC (0x01), ATAPI or SFF-8020i (0x02), QIC-157 (0c03),
* UFI (0x04), SFF-8070i (0x05), and transparent SCSI (0x06), selected by
* the optional "protocol" module parameter. In addition, the default
- * Vendor ID, Product ID, and release number can be overridden.
+ * Vendor ID, Product ID, release number and serial number can be overridden.
*
* There is support for multiple logical units (LUNs), each of which has
* its own backing file. The number of LUNs can be set using the optional
@@ -106,6 +106,7 @@
* vendor=0xVVVV Default 0x0525 (NetChip), USB Vendor ID
* product=0xPPPP Default 0xa4a5 (FSG), USB Product ID
* release=0xRRRR Override the USB release number (bcdDevice)
+ * serial=HHHH... Override serial number (string of hex chars)
* buflen=N Default N=16384, buffer size used (will be
* rounded down to a multiple of
* PAGE_CACHE_SIZE)
@@ -270,6 +271,8 @@

#define DRIVER_DESC "File-backed Storage Gadget"
#define DRIVER_NAME "g_file_storage"
+/* DRIVER_VERSION must be at least 6 characters long, as it is used
+ * to generate a fallback serial number. */
#define DRIVER_VERSION "20 November 2008"

static char fsg_string_manufacturer[64];
@@ -314,6 +317,7 @@ static struct {
unsigned short vendor;
unsigned short product;
unsigned short release;
+ char *serial_parm;
unsigned int buflen;

int transport_type;
@@ -374,6 +378,9 @@ MODULE_PARM_DESC(product, "USB Product ID");
module_param_named(release, mod_data.release, ushort, S_IRUGO);
MODULE_PARM_DESC(release, "USB release number");

+module_param_named(serial, mod_data.serial_parm, charp, S_IRUGO);
+MODULE_PARM_DESC(serial, "USB serial number");
+
module_param_named(buflen, mod_data.buflen, uint, S_IRUGO);
MODULE_PARM_DESC(buflen, "I/O buffer size");

@@ -3197,6 +3204,7 @@ static int __init check_parameters(struct fsg_dev *fsg)
{
int prot;
int gcnum;
+ int i;

/* Store the default values */
mod_data.transport_type = USB_PR_BULK;
@@ -3272,6 +3280,48 @@ static int __init check_parameters(struct fsg_dev *fsg)
ERROR(fsg, "invalid buflen\n");
return -ETOOSMALL;
}
+
+ /* Serial string handling.
+ * On a real device, the serial string would be loaded
+ * from permanent storage. */
+ if (mod_data.serial_parm) {
+ const char *ch;
+ unsigned len = 0;
+
+ /* Sanity check :
+ * The CB[I] specification limits the serial string to
+ * 12 uppercase hexadecimal characters.
+ * BBB need at least 12 uppercase hexadecimal characters,
+ * with a maximum of 126. */
+ for (ch = mod_data.serial_parm; *ch; ++ch) {
+ ++len;
+ if ((*ch < '0' || *ch > '9') &&
+ (*ch < 'A' || *ch > 'F')) { /* not uppercase hex */
+ WARNING(fsg,
+ "Invalid serial string character: %c; "
+ "Failing back to default\n",
+ *ch);
+ goto fill_serial;
+ }
+ }
+ if (len > 126 ||
+ (mod_data.transport_type == USB_PR_BULK && len < 12) ||
+ (mod_data.transport_type != USB_PR_BULK && len > 12)) {
+ WARNING(fsg,
+ "Invalid serial string length; "
+ "Failing back to default\n");
+ goto fill_serial;
+ }
+ fsg_strings[FSG_STRING_SERIAL - 1].s = mod_data.serial_parm;
+ } else {
+fill_serial:
+ fsg_string_serial_fill(fsg_string_serial, DRIVER_VERSION);
+ }
+
+#else /* !CONFIG_USB_FILE_STORAGE_TEST */
+
+ fsg_string_serial_fill(fsg_string_serial, DRIVER_VERSION);
+
#endif /* CONFIG_USB_FILE_STORAGE_TEST */

return 0;
@@ -3447,8 +3497,6 @@ static int __init fsg_bind(struct usb_gadget *gadget)
init_utsname()->sysname, init_utsname()->release,
gadget->name);

- fsg_string_serial_fill(fsg_string_serial, DRIVER_VERSION);
-
fsg->thread_task = kthread_create(fsg_main_thread, fsg,
"file-storage-gadget");
if (IS_ERR(fsg->thread_task)) {
--
1.7.1